216 tappets while running

[harrygrey382]

Just about to retighten the head and do the valve adjust (run probably an hour tops since rebuild about 10 years ago). The manual says to set at .06 and .13 cold then adjust to .1 and .2 hot while running (it sresses this). What's the procedure here, and do you bother? I just did the valves on a toyota 2H hot and got them done before it cooled much at all...

[lynx42]

Harry,

It is the easiest thing to do and you will get them really good and quiet.

Just bring the engine up to temperature and remove the rocker cover. Start the engine, set the running at minimum revs, loosen the locking nut one pushrod at a time and slip the feeler gauge between the valve stem and the rocker. Tighten or loosen the adjuster nut until you get the right clearance and tighten the lock nut. Do this for all of the valves and the job is done. Easy and simple to do. You can start anywhere on any valve and if one is still a bit noisy, just go back and do it again,

Hope this helps.

Regards Rick.

[motto]

Exactly as Rick describes is how my dad taught me to set them. It's not difficult at a low idle using a ring spanner and a well fitting screw driver. You are far better off doing it with assistance. One on the tools and one on the feeler gauges.

The final settings according to my TM are .006" to .008" for the inlets and .013" to.015" for exhausts. For heavy duty operation it specifies .010" and .020".

David

[harrygrey382]

Thanks guys. So I guess you're doing moving the feeler gauge in and out when the valve is stationary? Are the only reasons to doing it running to keep the engine temp consistent and to not have to move the crank? Also how much oil mess is there?

MY MB-C1 manual lists the valve clearences at temps from 0 to 30 mins startging at .006I and .013E (interestingly same clearance at operating temp too) but says to adjust them at .01 and .02 later. But then it says adjust exhaust to .015 for quietest running and if "the vehicle is not to be used in high engine speed service or heavy going". I doubt this is ever going to work very hard, but the country round here is steep and I have some good sized timber in mind for later on

[motto]

There is no oil loss normally. The engine speed is to low to cause splash and the raised ridge around the outside edge that the gasket sits on stops it flowing anywhere but down the push rod holes.

There is no difficulty in feeling the amount of drag on the gauge and with two of you working the job is done quite quickly unlike doing one then rotating to another each time.

The figures I gave came from a manual for a 1-1/2 ton truck so take your pick.Err in favour of bigger rather than smaller gaps as these engines are a little prone to burning valves.

David

[harrygrey382]

ok great, just need to fill'er up with coolant then I'll give it a go. I'll be on my own as none of the other blokes here are up to it I think, or at least I don't trust them to be...

This manual covers all Chev blitzs and I er on the side of larger gaps so I'm happy with .01 and .02

[Bob McNeill]

caution, with clearance of 0.01 and 0.02, the 0.01 sounds OK but 0.02 is too wide and are you running the valves with the caps on or off, in the manual it gives the change in clearance as engine warms up, I,d bring the exhaust down to 0.012- 0.015. my 2c worth.

[Phil Waterman]

Hi Harry

From your recent post I assume you are doing this on your C15 without the body installed, which makes it easier than it will be once the body and nose are there, and we won't even talk about trying to do it on Pat 11 and 12 on those even once you remove all the dog house sheet metal it isn't easy.

There have been several good threads on this in the past that had some useful information take a look at http://www.mapleleafup.net/forums/sh...ad.php?t=11791 About half way down the page there is a post from Keith Orpin with a useful bit of information about which cylinders can be done at the same time if you are using the engine not running approach.

Concerning oil splashing around with the cover off is minimal even with the later 261 with 40PSI oil pressure. Take a look at some of the engine video on my web site you can see the engines running with the covers off.
http://canadianmilitarypattern.com/EngineTesting.htm take a look at the 235 videos they also show the engine running with a clear side cover on the test stand.

For me I seem to get better results setting the valves with the engine hot not running. Have done it both ways with the engine at room temperature with the engine on the test stand just to get a starting point. Then later when the engine has had a chance to run in with the engine hot. Biggest issue is to wait until the oil in the engine has reached operating temperature so the whole engine is really at that 160-180 F range. When I'm doing this on the test stand I use a water jacket block heater. Which will maintain the block temp for a long time after you run the engine. Minimum engine run time to get to equalized temperature assuming 68-70F air temp is about 1/2 hour.

Cheers Phil

[harrygrey382]

Thanks for the info links Phil, yep thankfully I'm doing it without the body. In fact I'll probably get everything just right mechanically before I even think about the body. Besides it puts off the time when I have to buy paint... That's quite a set up you had their! I've certainly never done testing to that extent. Couldn't find the footage of running with no cover though.

Originally Posted by Bob McNeill

caution, with clearance of 0.01 and 0.02, the 0.01 sounds OK but 0.02 is too wide and are you running the valves with the caps on or off, in the manual it gives the change in clearance as engine warms up, I,d bring the exhaust down to 0.012- 0.015. my 2c worth.

Yeah I can see the change in clearance with temperature, and it supports what someone says in the thread Phil linked to that clearance is the same cold and hot. Why do you then .02 is too wide when the manual specifically states it? Not being a smart arse just wondering? I know .02 is for heavy conditions, but you say caution to it - how come? I understand the problems with too bigger gaps but why would the manual be recommending something incorrect?

[Bob McNeill]

I,ve found that the engine ran quieter and didn,t hammer the rockers or bell the valve stem, maybe our fuel is different, as this engine did not perform as well in the UK and France but once back in Aus settled down until it cracked a piston which allowed the little end bush to become loose and gouge the cylinder wall. A 216 engine I bought didn,t have the caps on the valves and to get valves out required valve stems to be ground to fit thru guides.

[Phil Waterman]

Hi Harry

Here is the link to the video of the 235 running with the side cover off http://canadianmilitarypattern.com/R...20003%20--.wmv .

I've got one of 216 which I will have to find. My reason for bothering to make a Lexan cover was I wanted to understand the engine a little better, see if the lifters rotated etc. and also to understand why the side covers leak. With a half an inch of oil standing in the oil gallery the leak cause is evident.

All of this family of inline 6 Chevy have a very high capacity oil pump. In the 216 spray lubrication they don't develop that much pressure but pump a lot of oil.

As to the valve ends getting mushroomed I have never encountered that with or without the covers. When ever replacing valves particularly exhaust I don't use NOS valves instead there is a modern V8 valve which interchanges which gives you a much harder valve using those I have avoided problems with burning valves.

On the subject of burning valves, with the solid lifters be very careful about getting the valve clearance to small in trying to get rid of valve noise. Some of the civilian car manuals list at less Exhaust .013 to .015 and trucks at .018 to .020 one manual I have even says trucks which are not run at high speed or heavy load can be set to .015 if quieter operation is desired.

My experience is that if the valve train is set to the CMP values hot of Exhaust .020 and Intake .010 they make a little noise but if that noise goes away you actually have a problem. It depends a lot how hard you work the engine with the 3 tons it is much more of problem than with the HUPs and C15s. With the bigger trucks the engines really are working hard when you are driving down the high way. Just a little wear on the valve faces and/or the valve seats the clearance goes to "0" and from there to not closing very quickly and with an exhaust valve a burned valve and real loss of power can be just a few miles of driving.

I burn a 3/8" notch in an exhaust valve in 40 miles on the highway. How did I know it was that little of time? Two reasons, first I have a vacuum guage mounted on that truck and it started flicking at idle as the valve died. Second on the way over the truck had its normal power on the way back it lost a lot of power. When I pulled the cover to work on the truck the exhaust valve that was burned was the only one with no clearance. Fortunately it did damage the valve seats so I replaced all of the exhaust valves with the new harden valves and ran that engine for many years before up engining to the 261.

Have they removed the Zinc from the oil sold in Australia? If so that may be another valve train wear problem to keep in mind.

Cheers Phil